Process of calibrating and justifying parts of wind musical instruments.



E. FOSTER.

PROCESS OF CALIBRATING AND JUSTIFYING PARTS OF wmo MusmAL msmuwzmsx APPLICATION HLED APR.15, i914.

iaftented 3am, 1917.

1 than 1w 1 .5,

UNITED STATES PATENT OFFICE.

EUGENE L. FOSTER, OF ELKHART, INDIANA, ASSIGNOR TO CHARLES G. CONN, OF ELKHART, INDIANA.

PROCESS OF CALIBRATING AND J USTIFYIN G PARTS OF WIND MUSICAL INSTRUMENTS.

Specification of Letters Patent.

Patented Jan. 2, 1917.

Application filed April 16, 1914. Serial No. 832,286.

To all whom it may concern,-

Be it known that I, EUGENE L; FosTER, a citizen of the United States, residing at Elkhart, in the county of Elkhart and State of Indiana, have invented a new and useful Process of Calibrating and Justifying Parts of WVind Musical Instruments, of which the following is a specification.

In wind musical instruments made of metal tubes, straight pieces can be formed by mandrels and by drawing, with fairly satisfactory results, but great difliculty is encountered in producing by known methods pieces that are uniformly accurate in bore and other dimensions, even when straight, and especially when the pieces involve the essential characteristics of curving and gradual and uniform tapering from end to end; and where such pieces have been produced with any degree of perfection, it has been accomplished only by the expenditure of the utmost care, great labor and considerable time upon each individual piece, and even then there was no certainty that the piece, when finished and embodied in an instrument, would produce a standard tone, so that not infrequently, the most expensive instruments after completion, required to be taken apart and altered at considerable expense, not to mention the numerous pieces condemned and discarded Without being embodied in an instrument.

The present invention has for one of its objects to provide a process whereby any number of parts may be made quickly and inexpensively with absolute uniformity as regards their correspondence with a selected standard of shape and dimensions; or in other words, it is an object of the present invention to provide a reliable process for accurately calibrating the hollow parts of at the ends of the molding space; introducing into the mold space, a tubular instrument part roughly formed to correspond with the ultimate shape, then forcing the part to a firm seating within the mold, then firmly gripping and holding the ends of the part relatively to the mold, and finally i11- troducing a fluid pressure medium with suflicient force to draw the metal of the tube, while its ends are being held, and expanding it into intimate contact and conformity with the molding space.

The invention will be fully understood upon reference to the accompanying drawing, in which- Figure l is a view of one-half of a mold having the roughly formed work-piece introduced thereinto and the combined pressure supply and gripping nozzles ready to be advanced to their work. Fig. 2 is a similar view with the nozzles forced into position, but before pressure is applied, and Fig. 3 is a view corresponding to Fig. 2, showing the conditions after the pressure has been applied.

1 represents one-half of a mold which preferably consists of two heavy steel bodies adapted to be-brought together and clamped so as to form a rigidly defined molding chamber 2 between them.

3 represents a roughly formed instrument part adapted to be introduced into and to lie with considerable freedom in the molding space.

4 and 5 represent clamping and pressure medium delivery nozzles adapted to be forced with considerable pressure into the ends of the work-piece 3 while the latter are sustained externally, as for instance by having the nozzles enter within the ends of the molding space; said nozzles being tapered so that they not only fit tightly within the ends of the workpiece, but expand the latter within safe limits against the mouth openings 2 and 2 which are correspondingly tapered, so that there is not only a sufliciently tight fitting of the nozzles in the tubular work-piece to confine fluid pressure medium under very high pressure, but there is a firm clamping of the ends of the workpiece against the tapered seats or openings, with the result that the ends can not draw inwardly during the expansion of the whole work-piece under the pressure of the fluid, or if drawn inward, it is not in correspondence with the transverse expansion or" the.

tube, and consequently, there is not only a reshaping of the partwhich makes it more accurate in its influence upon the vibratory air column in the production of the musical note, but a change in structure oi said part which better adapts it to serve its purpose as a part of a wind musical instrument.

There is a further characteristic of the process, particularly when applied to curved parts, such as illustrated in the drawing, namely, that in forcing the nozzles into the ends of the work-piece with sufiicient pressure to expand said ends against their tapered seats, the work-piece is forced fully into the molding space, so that instead or" occupying the position of Fig. 1', the outer curve lies snugly against the corresponding wall of the molding space, with the result that the distribution of metal in the finished piece is better, particularly since the prin cipal space to be filled is then on the shorter arc, and the filling of this space is by a shortening of the are rather than enlarging it, This is of special advantage where the tube is made from sheet metal having a brazed or soldered seam along the curved side.

After the pressure is introduced which would be suiiicient to force the walls of the tube into intimate contact throughout, the work-piece will lie to the mold as suggested in Fig. 3.

In practice, the two nozzles will prefer ably be carried on a suitable press which develops the pressure of the fluid medium, or upon other suitable/mountings, and the mold will be supported upon a carriage which adapts the mold to be forced under considerable pressure toward the nozzles, until the latter have entered into the proper relation with the ends of the tube.

I claim l. The process of calibrating and justifying tubular parts of wind musical instru ments which consists in introducing, into a mold accurately conforming to the dimensions and shape ultimately desired, a tubular work-piece approximating such shape and dimensions; firmly clamping and holding the ends of said work-piece relatively to the ends of the mold space; and then introducing into the work-piece a pressure medium under sufficient pressure to draw and stretch the metal of the work-piece and give to its walls a permanent set in close contact with the walls of the mold.

2. The process of calibrating and justifying curved tubular parts of wind musical instruments which consists in introducing, into a mold having a curved molding chamber accurately conforming to the dimensions and shape ultimately desired, a tubular work-piece approximating such shape and dimensions; forcing the end members of said work-piece toward the curve 01" the mold space; then firmly clamping and holding the ends of said workpiece relatively to the ends of the mold space; and then introducing into the workpiece a pressure medium under suificient pressure to draw and stretch the metal of the work-piece and give to its walls a permanent set in close contact with the walls of the mold.

S. The process of calilu'a-ting and justifying uniformly tapered and intermediately curved tubular parts of wind musical instruments which consists in introducing, into a mold having a curved molding chamber accurately conforming to the dimensions and shape ultimately desired, a tubular workpiece approximating such shape and dimensions forcing the end members of said workpiece toward the curve of the mold space and then firmly clamping and holding the ends of said work-piece relatively to the ends of the mold space; and then introducing into he work-piece a pressure medium under sufficient pressure to draw and stretch the metal of the work-piece and give to its walls a permanent set in close contact with the walls of the mold.

The foregoing specification signed at Elle hart, Ind. this thirteenth day of April, 1914,

EUGENE L. FOSTER.

In presence of P. H. SHIFNER, W. I. l/Vrrrrn.

Gopies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, I d. 

